Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add iliaal/whetstone --skill postgresqlgit clone --depth 1 https://github.com/iliaal/whetstoneWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/iliaal/whetstone/postgresql)<a href="https://agentmods.dev/skills/iliaal/whetstone/postgresql"><img src="https://agentmods.dev/badge/skills/iliaal/whetstone/postgresql/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/iliaal/whetstone/postgresql"><img src="https://agentmods.dev/badge/skills/iliaal/whetstone/postgresql.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00061 | $0.01474 |
| Opus 5.5 | $0.00024 | $0.00590 |
| Sonnet 5.5 | $0.00012 | $0.00295 |
| Haiku 4.5 | $0.00006 | $0.00147 |
Grade A, and why
postgresql scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 139 lines — stays where its author put it; the contents beside it link to each section on GitHub.
PostgreSQL
Data Type Defaults
| Need | Use | Avoid |
|---|---|---|
| Primary key | BIGINT GENERATED ALWAYS AS IDENTITY |
SERIAL, BIGSERIAL |
| Timestamps | TIMESTAMPTZ |
TIMESTAMP (loses timezone) |
| Text | TEXT |
VARCHAR(n) unless constraint needed |
| Money | NUMERIC(precision, scale) |
MONEY, FLOAT |
| Boolean | BOOLEAN with NOT NULL DEFAULT |
nullable booleans |
| JSON | JSONB |
JSON (no indexing), text JSON |
| UUID | gen_random_uuid() (PG13+) |
uuid-ossp extension |
| IP addresses | INET / CIDR |
text |
| Ranges | TSTZRANGE, INT4RANGE, etc. |
pair of columns |
Schema Rules
- Every FK column gets an index (PG does NOT auto-create these)
NOT NULLon every column unless NULL has business meaningCHECKconstraints for domain rules at DB levelEXCLUDEconstraints for range overlaps:EXCLUDE USING gist (room WITH =, during WITH &&)- Default
created_at TIMESTAMPTZ NOT NULL DEFAULT now() - Separate
updated_atwith trigger, never trust app layer alone - Use
BIGINTPKs — cheaper JOINs than UUID, better index locality
Index Strategy
| Type | Use When |
|---|---|
| B-tree (default) | Equality, range, sorting, LIKE 'prefix%' |
| GIN | JSONB (@>, ?, ?&), arrays, full-text (tsvector) |
| GiST | Geometry, ranges, full-text (smaller but slower than GIN) |
| BRIN | Large tables with natural ordering (timestamps, serial IDs) |
Index rules:
- Composite: most selective column first, max 3-4 columns
- Partial:
WHERE status = 'active'— smaller, faster - Covering:
INCLUDE (col)— avoids heap lookup - Expression:
ON (lower(email))— for function-based WHERE - Drop unused indexes:
SELECT * FROM pg_stat_user_indexes WHERE idx_scan = 0
JSONB Patterns
-- GIN index for containment queries
CREATE INDEX ON items USING gin (metadata);
SELECT * FROM items WHERE metadata @> '{"status": "active"}';
-- Expression index for specific key access
CREATE INDEX ON items ((metadata->>'category'));
SELECT * FROM items WHERE metadata->>'category' = 'electronics';
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 139 lines · 61 tokens per session scan A 6fc8e4d45029
postgresql is a skill published in the GitHub repository iliaal/whetstone (35 stars, last pushed 2d ago), licensed MIT. It adds 61 tokens to every session and 1,474 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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